ANNEX. 1. GENERAL FACTORS GOVERNING THE USE OF AIRBORNE TROOPS. (a) Airborne troops might be used against this country either (i) with the object of attacking and sabotaging key points, such as aircraft and other important factories engaged in war production, concentrations of aircraft, (e.g. in reserve parks), communications and public utilities, with the object of crippling our war effort; or (ii) as the opening phase of invasion. (b) The first object could not be expected to have a conclusive effect on our power to continue the war, and therefore could only be regarded as of long-term value.